Homochirality, the uniformity in single molecular handedness, is a defining feature of life. Although universal in biology, the evolutionary advantage of selecting one enantiomer over its mirror image remains unresolved. One possible clue may lie in catalysis itself: recent studies demonstrate that oxygen evolution reaction (OER), a key step in photosynthesis, is sensitive to chirality. Here, we report that electrochemical OER performance with chiral additives may be correlated to the alignment of their electric (ETDM) and magnetic (MTDM) transition dipole moments in the lowest-energy transition. Enantiomers with parallel ETDM-MTDM configurations consistently outperform their antiparallel counterparts. Notably, this bias also manifests in natural systems, suggesting a shared stereoelectronic principle. We define this stereoelectronic correlation as the Supplementary Angle Effect (SAE). Our findings establish SAE in electrocatalysis offering a quantitative descriptor for assessing how molecular handedness affects catalytic behavior and enantiodifferential performance.

Alzheimer's disease (AD) is the leading cause of dementia, and early identification of molecular biomarkers in blood offers a promising avenue for diagnosis and monitoring treatment. Tau-441 stands out as a particularly promising biomarker among the potential molecular targets. This research describes the development of a highly sensitive and cost-effective biomimetic sensor, capable of selectively detecting Tau-441 at femtomolar concentrations. This is achieved through the synergistic combination of gold nanoparticles (AuNPs) with molecularly imprinted polymer (MIP) technology. The MIP layer was sensitised by electropolymerising phenylenediamine (o-PDA) in the presence of Tau-441 and AuNPs onto a gold screen-printed electrode (Au-SPE) using cyclic voltammetry (CV). After polymerisation, the entrapped proteins were removed by proteolytic digestion, generating well-defined imprinted cavities within the polymer matrix. Scanning electron microscopy (SEM) and Raman analysis were conducted to monitor the surface modification of the Au-SPE working electrode. The device displayed linear responses to Tau-441 protein within the range 2.0 pg mL-1 to 200 ng mL-1, with a limit of detection of 1.51 fg mL-1. The analytical performance of the device was validated in complex matrices, including Cormay serum and cell media from primary cultures of hippocampal neurons, using a competitive assay. The platform showed high sensitivity, good reproducibility, and reliable performance in biologically relevant media, demonstrating strong robustness. Its excellent analytical characteristics, together with the potential for integration into portable electrochemical devices, make this sensor a promising tool for rapid and accurate point-of-care testing, enhancing the detection and monitoring of AD.

Early diagnosis of Alzheimer's disease (AD) remains challenging, creating an urgent need for sensitive, rapid and non-invasive technologies for the detection of blood-based biomarkers. Here, we report an electrochemical immunosensor for the direct detection of phosphorylated tau protein (tau 181), a key biomarker associated with early-stage AD. The sensing interface combines a redox-active poly(toluidine blue) (p(TB)) layer with gold nanostructures, including spherical nanoparticles (AuNPs) and branched nanostars (AuNSs), enabling external redox probe-free detection. The electropolymerized p(TB) acts as an intrinsic redox mediator, while the nanostructures enhance surface area, antibody immobilization and electron transfer. Cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS) confirmed that interfacial charge transfer processes are strongly dependent on nanostructure morphology, with optimal performance obtained using 0.06 mM AuNPs. Direct quantification of tau 181 was achieved by square wave voltammetry (SWV), providing a wide linear detection range (1 pg/mL-100 ng/mL) and an ultra-low limit of detection of 1.09 pg/mL, which is below the clinically relevant threshold for AD diagnosis (2-4 pg/mL). The immunosensor also demonstrated excellent reproducibility and selectivity. By coupling a redox-active polymer with colloidal gold nanostructures on a disposable electrode platform, this work provides mechanistic insight into nanostructure-mediated electron transfer and establishes a promising biointerface for fast and sensitive AD biomarker detection for clinical screening applications.

The spread of point-of-care (PoC) glucose sensor technologies is crucial for effective diabetes management. In this context, we present a novel electrochemical biosensing platform that integrates various carbon allotropes—biographene (BGr), zinc oxide (ZnO)–modified multi-walled carbon nanotubes (MWCNT-ZnO), and biologically derived carbon dots (CDs)—in a polyaniline-based matrix (PANI) for glucose detection. The sensing layer was prepared by electropolymerizing aniline in the presence of the individual carbon allotropes and the enzyme glucose oxidase (GOx) on the surface of a screen-printed gold electrode (Au-SPE). The analytical performance of the sensor was evaluated by chronoamperometry (CA) in phosphate-buffered saline (PBS) and glucose-spiked human serum. The morphology and chemical composition of the carbon allotropes were characterized by using scanning electron microscopy (SEM) and X-ray photoelectron spectroscopy (XPS). Among the sensors tested, the carbon dot (CD)–based sensor demonstrated the best analytical performance, with a limit of detection (LOD) of 1.08 mmol/L and a sensitivity of 0.453 μA per decade of glucose concentration. This covers a linear working range of 1.56 to 75.0 mmol/L, which includes the typical physiological glucose concentration range observed in both healthy individuals and individuals with diabetes. This study aims to improve enzymatic glucose biosensors using fructose-derived carbon dots and PANI to enhance enzyme immobilization, electron transfer, and sensitivity while maintaining low cost and sustainability, offering strong potential for applications in personalized health monitoring and long-term chronic disease management.

Oxygen evolution reaction (OER) is the rate-limiting step of the overall water splitting process. To promote this reaction holistic application, inexpensive, stable and environmentally friendly catalyst should be developed. This study is based on the usage of hydrothermally treated potato peels (HPP) as OER catalyst. To compete with well-performant benchmark catalysts, the unreported method of using UV laser activation (LA) was carried out. This, coupled to the water splitting process set-up optimization (electrodes selection, pH effect, catalyst loading and deposition method) as well as the use of an electrochemical activation (applying 350 consecutive voltammetry cycles) ensured the obtention of Ni foam-HPP-LA electrodes with an astonishing OER performance. Current density values of 10, 50 and 100 mA/cm(2) were obtained with low overpotentials of 360, 397 and 416 mV, respectively, and a low Tafel slope of 46.6 mV/dec revealed the quick OER kinetics. FTIR, SEM-EDS and XPS results explain these promising results, highlighting a homogeneous HPP distribution and the fact that laser and electrochemical activations enhanced functional groups presence. The optimal catalyst exhibited a high stability, requiring <1.4 % overpotential increase for keeping 10, 50 and 100 mA/cm(2) during 30 h each, obtaining minor physicochemical modifications, which are related to surface oxidation and molecules breakage.

Homochirality, the uniformity in single molecular handedness, is a defining feature of life. Although universal in biology, the evolutionary advantage of selecting one enantiomer over its mirror image remains unresolved. One possible clue may lie in catalysis itself: recent studies demonstrate that oxygen evolution reaction (OER), a key step in photosynthesis, is sensitive to chirality. Here, we report that electrochemical OER performance with chiral additives is determined by the alignment of their electric (ETDM) and magnetic (MTDM) transition dipole moments in the lowest-energy transition. Enantiomers with parallel ETDM–MTDM configurations consistently outperform their antiparallel counterparts. Notably, this bias also manifests in natural systems, suggesting a shared stereoelectronic principle. We define this stereoelectronic correlation as the Supplementary Angle Effect (SAE). Our findings establish SAE as a quantifiable descriptor for electrocatalysts and provide a conceptual basis for understanding the role of molecular handedness in catalysis and its possible evolutionary implications.

This research presents a novel, cost-effective, and scalable approach for the direct detection of myoglobin (Myo) in point-of-care (PoC) applications. In this strategy, redox-active Prussian Blue nanocubes (PBNCs) are applied to a disposable platinum screen-printed electrode (Pt-SPE). Subsequently, a biomimetic sensing layer is generated by electropolymerization of ortho-phenylenediamine (o-PD) in the presence of Myo, which forms molecularly imprinted polymer (MIP) sites by cyclic voltammetry (CV). The electropolymerization process takes place in a potential range of -0.2 V to +0.8 V, for five cycles at a scan rate of 50 mV/s, in a 10 mmol/L o-PD solution. After polymerization, the electrode is incubated in trypsin for 2 h to create Myo-specifically imprinted cavities. The structural and morphological properties of the biomimetic layer were analyzed by Raman spectroscopy, Fourier transform infrared spectroscopy (FTIR), and scanning electron microscopy (SEM). The direct detection of Myo was analyzed by differential pulse voltammetry (DPV). The results showed a linear response to Myo concentrations ranging from 1.0 ag/mL to 10 ng/mL, a limit of detection (LOD) of 0.76 ag/mL, and a R2 value of 0.9775. The absence of an external liquid redox probe simplifies the sensor design, improves portability, and reduces the complexity of the assay, making it more suitable for PoC.

Paper based point-of-care (PoC) detection platforms applying lateral flow assays (LFAs) have gained paramount approval in the diagnostic domain as well as in environmental applications owing to their ease of utility, low cost, and rapid signal readout. It has centralized the aspect of self-evaluation exhibiting promising potential in the last global pandemic era of Covid-19 implementing rapid management of public health in remote areas. In this perspective, the present review is focused towards landscaping the current framework of LFAs along with integration of components and characteristics for improving the assay by pushing the detection limits. The review highlights the synergistic aspects of assay designing, sample enrichment strategies, novel nanomaterials-based signal transducers, and high-end analytical techniques that contribute significantly towards sensitivity and specificity enhancement. Various recent studies are discussed supporting the innovations in LFA systems that focus upon the accuracy and reliability of rapid PoC testing. The review also provides a comprehensive overview of all the possible difficulties in commercialization of LFAs subjecting its applicability to pathogen surveillance, water and food testing, disease diagnostics, as well as to agriculture and environmental issues.

The Oxygen Evolution Reaction (OER) is the limiting step of the water splitting process for the attainment of valuable hydrogen. A green and economic catalyst is hereby synthesized to reduce the OER overpotential. For the first time, a set of representative agroindustry residues were used and subjected to pyrolytic and hydrothermal treatments, fitting them into circular economy. Hydrothermally treated potato peels (PP-HC), particularly, reached 10, 50 and 100 mA/cm2 at overpotentials of 353, 408 and 431 mV, respectively. The novel material showed good electron-transfer and small Tafel slope (52.2 +/- 0.2 mV/dec) that is explained by the presence of electronic rich bonds as confirmed by physical-chemical and electrochemical characterization. PP-HC showed an astonishingly high stability for 90 h or 8000 cyclic voltammetries, with the hydrochar suffering only slight modifications, as measured by FTIR and XPS. This innovative study opens a path to efficient and environmentally friendly green hydrogen.

Hyperthermia-based therapies have shown great potential for clinical applications such as for the antitumor and antipathogenic activities. Within all strategies, the so-called photothermal therapy proposes to induce the hyperthermia by the remote laser radiation on a photothermal conversion agent, in contact with the target tissue. This paper reviews the most relevant in vitro and in vivo studies focused on NIR laser-induced hyperthermia due to photoexcitation of graphene oxide (GO) and reduced graphene oxide (rGO). Relevant parameters such as the amount of GO/rGO, the influence of the laser wavelength and power density are considered. Moreover, the required temperature and exposure time for each antitumor/antipathogenic case are collected and unified in a thermal dose parameter: the CEM43. The calculated CEM43 thermal doses revealed a great variability for the same type of tumor/strain. In order to detect potential tendencies, the values were classified into four ranges, varying from CEM43 < 60 min to CEM43 ≥ 1 year. Thus, a preference for moderate thermal doses of CEM43 < 1 year was detected in antitumor activity, with temperatures ≤ 50 °C and exposure time ≤ 15 min. In case of the antipathogenic studies, the most used thermal dose was higher, CEM43 ≥ 1 year, with ablative hyperthermia (> 60ºC). The ability of GO/rGO as effective photothermal conversion agents to promote a controlled hyperthermia is proven. The variability found for the CEM43 thermal doses on the reviewed studies reveals the potentiality to evaluate, for each application, the use of lower temperatures, by modulating time and/or repetitions in the doses.

193 nm Excimer lasers are efficient tools to process group-IV semiconductors for advanced microelectronic and photonic devices through crystallization annealing, or strain engineering. The combination of both, high photon energy and low penetration depth of the 193 nm laser pulses allow breaking most covalent bonds with a single photon, and low thermal budget treatments through a precise control of the laser processed volume. Up to now, studies using 193 nm lasers for silicon carbide (SiC) processing are mostly limited to ablation processes for micromachining purposes. This paper presents a first study to demonstrate that the optimization of other processes, like the creation or annealing of vacancies, the alloying of SiC surfaces or the selective ablation of silicon or carbon should also be feasible. To develop such laser assisted processes and optimize process parameters, a numerical simulation of the laser/material interaction is essential. This implies that the temporal evolution of the laser pulse must be well known, and that an "in-situ measurement" of the response of the material to the laser pulse should be available. This study therefore evaluates the temporal profile of a new high-power Excimer laser, and presents the results of in-situ Time Resolved Reflectivity (TRR) measurements obtained when irradiating 4H-SiC(0001) wafers with radiant exposures ranging from 0,1 J/cm2 to 3,0 J/cm2. The temporal pulse profile is determined, fitted and applied in a 1-D numerical simulation of the temperature gradients for Si(100) as reference sample, to validate the experimental findings. Radiant exposure thresholds at around 1,4 J/cm2 to locally produce molten surfaces and 1,8 J/cm2 to ablate and create carbon-rich regions with graphene, are determined in-situ and confirmed by Raman spectroscopy.

Chiroptical responses are valuable for the structural determination of dissymmetric molecules. However, the development of everyday applications based on chiroptical systems is yet to come. We have been earlier using axially chiral allenes for the construction of linear, cyclic, and cage-shaped molecules that present remarkable chiroptical responses. Additionally, we have developed chiral surfaces through upstanding chiral architectures. Since the goal is to obtain robust chiroptical materials, more recently we have been studying spirobifluorenes (SBFs), a well-established building block in optoelectronic applications. After theoretical and experimental demonstration, the suitability of chiral SBFs for the development of robust chiroptical systems was certified by the construction all-carbon double helices, flexible shape-persistent macrocycles, chiral frameworks for surface functionalization, and structures featuring helical or spiroconjugated molecular orbitals. Here, we give an overview of our contribution to these matters.

In recent years, the development of flexible and wearable devices for healthcare and biomedical applications has become an emerging technological goal, particularly with personalized medicine on the rise. As a response to the increasing demand for in-situ sensing platforms that fulfil some essential requirements like sensitivity, reproducibility and high stability, electrochemical sensors have boosted their way for innovative approaches. So, high-quality flexible sensing strategies are still a demand for local monitoring.Herein, a flexible three-electrode system was fabricated on transparent polymeric sheet substrate through physical deposition of gold as working, counter, and reference electrodes. Along the fabrication process, the electrochemical performance of these electrodes was assessed by means of cyclic voltammetry (CV) while gold adherence to the plastic material was continuously improved. Afterwards, a high-performance molecularly-imprinted sensing film inspired by natural recognition mechanism was assembled through electropolymerization of phenol monomer, in the presence of 3-nitrotyrosine (3-NT), directly on the gold surface. Under the optimized conditions, the flexible (bio)sensor platform was able to detect the presence of 3-NT over the concentration range 10 pg/mL – 1 μg/mL, enabling one of the lower limits of detection found in the literature (1.13 pg/mL or 24.9 pM). The obtained (bio)sensor displayed good reproducibility, stability and selectivity over the chosen interfering substances.Overall, the developed electrochemical device may serve as a flexible, miniaturized, and reliable platform, with potential to be applied in the future as wearable sensing technology.

We examine the Raman shift in silicon-germanium-tin alloys with high silicon content grown on a germanium virtual substrate by molecular beam epitaxy. The Raman shifts of the three most prominent modes, Si-Si, Si-Ge, and Ge-Ge, are measured and compared with results in previous literature. We analyze and fit the dependence of the three modes on the composition and strain of the semiconductor alloys. We also demonstrate the calculation of the composition and strain of SixGe1 - x - ySny from the Raman shifts alone, based on the fitted relationships. Our analysis extends previous results to samples lattice matched on Ge and with higher Si content than in prior comprehensive Raman analyses, thus making Raman measurements as a local, fast, and nondestructive characterization technique accessible for a wider compositional range of these ternary alloys for silicon-based photonic and microelectronic devices.

How sterilization techniques accurately affect the properties of biopolymers continues to be an issue of discussion in the field of biomedical engineering, particularly now with the development of 3D-printed devices. One of the most widely used biopolymers in the manufacture of biomedical devices is the polylactic acid (PLA). Despite the large number of studies found in the literature on PLA devices, relatively few papers focus on the effects of sterilization treatments on its properties. It is well documented in the literature that conventional sterilization techniques, such as heat, gamma irradiation and ethylene oxide, can induced damages, alterations or toxic products release, due to the thermal and hydrolytical sensitivity of PLA. The purposes of this paper are, therefore, to review the published data on the most common techniques used to sterilize PLA medical devices and to analyse how they are affecting their physicochemical and biocompatible properties. Emerging and alternative sterilization methods for sensitive biomaterials are also presented.

Theoretical simulations predict that direct band transitions are favored in Germanium-Lead (GePb) alloys with Pb concentrations of cPb Ĭ 3.4%. This could enable the creation of semiconductor lasers that are directly structured on Ge substrates. However, the formation of alloys with these properties is hindered by the low equilibrium solubility of Pb in Ge. Therefore, the usage of out-ofequilibrium growth methods, such as pulsed laser induced epitaxy (PLIE), is necessary. The contribution focusses on the formation of GePb alloys with varying Pb concentrations.

The authors report a novel approach to analyze the behavior of pulsed-laser-induced epitaxy on group-IV semiconductors by spectroscopic ellipsometry measurements and finite-element modeling of the thermo- and hydrodynamic behavior. Gradient-composition epitaxial crystals are obtained from previously atomically sharp heteroepitaxial samples through optically monitored processing with UV excimer laser pulses. Spectroscopic ellipsometry is employed to determine the composition gradient of the semiconductor alloy, and the results are correlated with energy-dispersive x-ray measurements. A finite-element modeling approach is developed based on the experimentally monitored melting dynamics and composition gradient results for understanding and prediction of the dynamics.

Chiroptical methods have been proven to be superior compared to their achiral counterparts for the structural elucidation of many compounds. To expand the use of chiroptical systems to everyday applications, the development of functional materials exhibiting intense chiroptical responses is essential. Particularly, tailored and robust interfaces compatible with standard device operation conditions are required. Herein, we present the design and synthesis of chiral allenes and their use for the functionalization of gold surfaces. The self-assembly results in a monolayer-thin room-temperature-stable upstanding chiral architecture as ascertained by ellipsometry, X-ray photoelectron spectroscopy, and near-edge X-ray absorption fine structure. Moreover, these nanostructures anchored to device-compatible substrates feature intense chiroptical second harmonic generation. Both straightforward preparation of the device-compatible interfaces along with their chiroptical nature provide major prospects for everyday applications.

While modulators, waveguides and detectors have been successfully integrated in silicon devices, a laser source still remains a challenge. Unfortunately, in silicon and germanium, indirect band transitions are favored, making laser emission unlikely. Direct bandgap transitions have recently been demonstrated in germanium by introducing tensile strain with heavy n-type doping or by alloying with Sn. GePb alloys seem to be promising candidates here as well, since the required Pb concentration is predicted to be far lower than for Sn. We examine the influence of SiO2 hard masks on the formation of GeSn and GePb by Pulsed Laser Induced Epitaxy, a method allowing fast processing and in-situ monitoring. Main objectives are to study the spatial distribution of elements and strain as well as the possible underetching of Ge after mask removal. Sn or Pb was deposited by thermal evaporation on an epitaxial Ge layer on Si(100), patterned with a SiO2 hard mask. The patterns were then irradiated with ArF excimer laser pulses of 193 nm wavelength to induce melting and resolidification processes, aligned to the crystal structure of the Si(100) substrate below. Extensive characterization was performed, mainly using Atomic Force Microscopy and Raman Spectroscopy, examining the fabrication quality, thus the feasibility of future integrated laser devices.

The design of new bioceramics requires a deep understanding of their structural characteristics using a combination of different characterization techniques. This paper offers an exhaustive Raman spectroscopy and X-ray diffraction study of two groups of bioceramics natural and synthetic, as well as of living tissues with different degrees of mineralization. Based on these results, two Raman-XRD correlation charts are proposed. Using a single Raman measurement, these charts are valuable tools for the identification of a number of structural parameters, such as the apatite phase percentage or crystallite size, of different calcium phosphate-based bioceramics and mineralized tissues.